[Coco] Technical OS9 Q.

[Bob Devries]

It is interesting to note that regardless of IT.SAS, the root directory is 
always allocated 7 sectors plus the FD sector. I'm assuming that the format 
command is responsible for this?
--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "Robert Gault" <robert.gault at worldnet.att.net>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Monday, January 23, 2006 9:05 AM
Subject: Re: [Coco] Technical OS9 Q.


> LSN0 should contain at DD.OPT ($3F) path descriptor options. That would 
> put a copy of PD.SAS at LSN0 $4D.
>
> Looking at some .dsk .os9 images on my PC indicates that this information 
> is available.
>
> Bob Devries wrote:
>> I'm wanting to add a directory entry into a OS-9 .dsk or .vhd file on the 
>> PC. Remember this is to run on the PC, and is programmed in PC C, not 
>> under OS-9.
>>
>> I've worked out that I need to first step through the directory, looking 
>> for a deleted file slot (starts with '\0').
>> If that fails, I need to add the new file to the end of the directory, 
>> OK, so that is no problem unless.....
>>
>> What if the directory allocation is fully utilised? That is, all the 
>> sectors originally allocated are used? I would need to allocate another 
>> block of sectors, but how will I know how many to allocate? Under OS-9, 
>> the create file routine would use IT.SAS from the device descriptor, but 
>> this value is not available to me.
>>
>> How should I proceed? Any clues? Suggestions?
>> -- 
>> Regards, Bob Devries, Dalby, Queensland, Australia
>>
>> Isaiah 50:4 The sovereign Lord has given me
>> the capacity to be his spokesman,
>> so that I know how to help the weary.
>>
>> website: http://www.home.gil.com.au/~bdevasl
>> my blog: http://bdevries.invigorated.org/
>>
>>
>
> -- 
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